abstract |
The present invention provides a method for directing highly cytotoxic maytansinoids to a target cancer-like cell population. For example, a cell binding substance-maytansinoid complex obtained by covalently binding a maytansinoid derivative modified with a sulfur-free non-cleavable linker represented by formula 7 and a cell binding substance is used. . [R is H or SO 3 Na + ] [Selection figure] None |